This invention relates to waterbeds and, more specifically, to an improved motion-control waterbed mattress. Waterbeds are ordinarily comprised of a rigid frame constructed of suitable plastic or wood supporting a bag-like enclosure which is filled with water through a water-filling means. The frame serves to confine the water-inflatable bag-like enclosure which is ordinarily constructed of vinyl or other suitable watertight flexible sheets.
The waves, the bottoming out and the edge collapsing created by the user's sitting, lying or moving on the waterbed mattress cause discomfort for the user or users thereby discouraging waterbed use. In the past, attempts have been made to suppress this discomfort problem with varying degrees of success. For example, baffles, tie-downs, and floats with tie-downs and/or baffles tied to the underside of the top and/or upper side of the bottom of the bag-like enclosure of the waterbed mattress have been employed to suppress motion. However, these conventional motion suppression means require additional watertight seams at high stress points which eventually fail ultimately resulting in water leakage.
Gelling agents have also been used in the past to suppress undesirable wave motion. But gell presents blending, heating and removal problems, its viscosity varies with the mineral content of differing water supplies employed and, upon its removal, more gelling agent is required to refill the mattress at considerable cost to the consumer.
Plastic foam inserts in the waterbed mattress constitute another approach to the control of undesirable wave motion and bottoming out. But plastic foam is excessively bulky, is difficult to package, handle and ship when disposed within the waterbed mattress, and when appreciably depressed to reduce bulk, it subsequently recovers an undesirably low percentage of its original dimension. Moreover, when the mattress containing foam inserts are water filled, the foam retains air which is extremely difficult to remove from the mattress. Additionally, the foam interferes with heat transfer in the water and acts as a sponge inhibiting water drainage.